All language subtitles for Through the Wormhole s06e03 Are We Here for a Reason.eng

What is the meaning of life?

Don't you believe there's
a reason for us being here?

Join the Greenleaf community.

We are, after all,
such sophisticated creatures,

the result of billions
of years of evolution.

Surely life is about more
than just our biological needs,

more than the daily rat race.

Is all the knowledge
we've gained

over the generations
aiming towards some final goal?

Are we architects
of our own fate?

Or is life just a series
of random accidents?

Is our existence
just a fluke of nature?

Or are we here for a reason?

Space, time, life itself.

The secrets of the cosmos
lie through the wormhole.

Captions by vitac...
www.Vitac.Com

captions paid for by
discovery communications

why are we here?

I know you've thought about it.

We all have.

What is our purpose?

What is our destiny?

We're born.

If we're lucky, we reproduce,

and then we die.

Repeat that a few billion times,

and you get from the first
simple life forms on Earth

to us.

Ever since Darwin,

scientists have been
working on how we got here.

But now they're asking
the question

we all seek the answer to...
Why?

Is all our wonderful complexity

directed
towards some greater goal?

Do our lives
have an ultimate purpose?

To English biochemist
Lee Cronin,

everything exists for a reason.

[ Bell dings ]

Even haggis,
the bizarre sheep stomach dish

that the Scots
can't get enough of.

Cronin:
Haggis exists because it's the Scottish national dish.

And it's been refined
for hundreds of years.

And that has a lot of parallels
with, actually, biology.

Freeman: 3.5 billion years ago,
the first living cell appeared.

Before that, Earth was just
a vast soup of chemicals.

Why did those chemicals combine
in just the right amounts

in just the right sequence
to become living things?

Lee is convinced that it
couldn't have been dumb luck,

just as a chef
can't invent haggis

by randomly throwing
ingredients together.

The invention of the haggis
recipe required feedback.

Cronin: So as information
passed back over time,

and the customer, if you like,
is going, "no, that's wrong,

that's wrong, that's awful."

And this gets better and better
and better,

until we get
to the perfect haggis.

Freeman:
Lee thinks the environment on early Earth played the role

of the chef's customer.

Cronin:
What we think happened is there is a natural law of evolution,

that it refines the chemicals
in steps over time,

where we can go from this easy,
to start with,

to this very special dish.

Freeman: If Lee is right,
the forces of evolution

were at work long before
the first cell.

Chemicals competed
against other chemicals.

To find out for sure,
Lee thought, why not play god

and try to evolve chemicals
into life forms in the lab?

This is a machine
that simulates

millions of years
of chemical evolution

in a matter of weeks.

Lee starts
with four simple chemicals

that can be mixed in 17 million
possible combinations.

So in the first step,

the ingredients
are selected by the machine.

And then, they are pumped
into the Wells here.

And they make random recipes.

They just select random amounts.

Freeman: The machine then
squirts out tiny blobs

of each chemical cocktail
into a water-filled petri dish.

It's videoing
the actual droplet behavior.

So it's looking at how much
the droplets are moving.

So that's one feature
that we want.

Another feature we're looking
for is droplets that divide,

so it's like replication.

Another property we're looking
for is droplets than can vibrate

and sense the environment.

Freeman: When the blobs
show signs of life,

that recipe
is selected for replication.

And the inferior recipes
are destroyed.

Then, with each generation,

the machine makes small,
random changes to the recipe.

After several weeks
of trial and error,

Lee's chemical blobs come alive.

They get mobile.

They hunt
and capture other droplets.

Cronin: Oh, that one...
There was a fusion.

Oh, it's done it.
That was nice.

Freeman:
They even reproduce.

If you found them outdoors,
you would probably mistake them

for little gelatinous
life forms,

even though they're not...
At least, not yet.

The next thing
we want to be able to do

is to feed the droplets
on their own

so they can take food naturally
from the environment

and grow and get
bigger and divide.

Then,
we're really on the pathway

to turning this random chemistry
into living chemistry,

into biology.

Freeman:
Evolutionary biologists

say that DNA in genes gives life
its foundational purpose,

to survive and evolve
to be better at surviving.

But if Lee is right,

DNA is not the only chemical
that can exist for this purpose.

This is why we're really
excited, because we can show

that evolution can occur
in the natural world

without genetic material.

Freeman: Lee believes
we are here for a reason,

a reason shared with all
life forms

and the chemicals
that constitute them...

To live,
to survive, and to evolve.

Cronin: Where there is energy
and there is matter,

chemistry transforms
into biology over time.

And this is a natural law.

At the deepest level,
inside every cell in our body,

we are driven

by the never-ending struggle
of chemicals

to make copies of themselves.

But if the only purpose of life
is to make more chemicals,

why did we ever
become more complex than this?

This guy can replicate
dozens of times a day,

reproducing its bag of chemicals

far more efficiently
than we can.

And yet, here we are.

What's the reason for bags
of chemicals like you and me?

Evolutionary biologist
Richard Lensky

at Michigan state university

is a biological time traveler.

So any biologist
would love to see the way

the film of life on Earth
played out

and to actually watch
the transitions that occurred

over these several billion years

and ask, "why did it work out
the way it did?"

Freeman: Richard doesn't have
billions of years

to watch evolution in action,

but he does have the span
of one lifetime,

which he has dedicated

to performing the longest
evolutionary experiment

in the history of science.

27 years ago,

Richard plucked

12 genetically identical E. Coli
bacteria from a container

and allowed them to start
their own populations

in 12 separate worlds.

Ever since, day after day,

he's watched each
of the 12 populations multiply

and compete amongst themselves
for a limited amount of food.

Lensky:
Key part of the experiment is just keeping it going,

day after day after day,

transferring a small amount
from each flask

into fresh medium each day.

And the bacteria grow and
replicate in that fresh medium

until they run out of the sugar
that they grow on.

And then, they sit there

until, the next day,
that whole process is repeated.

Freeman:
At the end of every day,

he allowed a small sample
of the survivors

to continue
producing new generations.

Year after year, the daily
process went on and on.

In each flask,
the cells of bacteria replicate,

passing on tiny,
random mutations

to their offspring's DNA.

For the first 15 years
of the experiment,

the separated populations
evolved pretty much in lockstep,

each strain gradually adapting
to this flask environment.

But one night,

one of the colonies had a sudden
and dramatic victory

in the arms race of evolution.

One day, we came in and found
that one of our flasks

had many more bacteria
than the others.

One of the lines of bacteria,

after they had finished
the glucose, they said, "hmm,

there's something else to eat."

And that gave them
a huge advantage.

Freeman:
Overnight, these E. Coli

had switched on new
and complex internal machinery

that allowed them
to extract energy

from a benign chemical additive.

Armed with this new talent,

they vanquished
their competitors.

But when Richard examined
the DNA of these E. Coli,

he realized that the mutation
that switched on the new talent

was merely the last
in a long series.

The others had lain dormant
for thousands of generations.

Richard thinks of it
as life playing a grand version

of his favorite game, poker.

Lensky:
I always liked playing games that involved a mixture

of luck and skill.

Most card games,
you've got the shuffling,

and yet poker takes some skill
to make a lot of money.

Freeman:
For E. Coli and humans alike,

each genetic mutation is like
a new card dealt to the species.

If the right hand
is made in the right order,

the organism
can win big for posterity.

Lensky:
In this case, the bacteria have this key mutation,

but it had to happen
in the context

where there were other mutations
before it.

Freeman:
When there is a queen and a king of hearts on the table,

and you have the 10 and
Ace of hearts in your hand,

you are set up to
potentially make a royal flush,

the most powerful hand in poker.

All you need is for the final
card to be a Jack of hearts.

Well, if you were looking
for a third seven,

that does you no good at all.

But if you've got the other
parts of a royal flush,

you're happy.

Freeman:
E. Coli adapt to meet their immediate needs

through genetic mutation.

But some mutations
don't have an immediate reward.

They are investments
for their distant descendants

so that they can win
a big evolutionary jackpot.

It's a purpose
that Richard sees mirrored

in the story of his own work
and in his own species,

homo sapiens.

Thousands of generations
of those who came before him

adapted to meet
their immediate needs

but also made tiny contributions

that set Richard up
to be a Jack of hearts.

They allowed him to run
an experiment

that forever changed humanity's
understanding of evolution,

one that would be carried on
by his prot�g�s

long after he's gone.

Could this be the purpose
of all life,

from simple single cells
to human beings?

Well, my wife says my purpose in
life is to take out the garbage.

But I do have a couple
of other purposes.

I don't know what the deepest
possible meaning of life is.

So many happenstances
and contingencies

and lucky events went into it.

To me,
that's just an amazing story

that I'm one tiny,
little speck of,

and I'm very glad
to be a part of it.

Freeman:
Why do we so desperately search for the meaning of life?

Perhaps it is because we must.

New science suggests that,
50,000 years ago,

human beings
dramatically transformed.

And ever since,
the survival of our species

depends on each of us
finding our unique purpose.

When you look at yourself
in the mirror,

do you see the person
you truly believe you are?

I'm lucky.

I discovered that I have a love
and a talent for acting.

What's your reason
for being here?

We're often told
that our purpose

can be anything
we want it to be.

New evidence suggests
that may not be true.

Evolution may have required

that each of us be born
with a specific purpose.

What is the meaning of life?

Geneticist Razib Khan says
that the answer is different now

than it was
for our prehistoric ancestors.

The change began with
the explosion of... agriculture

and the rise of an entirely new
class of animal.

The wild ancestors
of these animals would have

violently attacked Razib
for threatening their territory.

But now,
these domesticated descendants

cuddle up to him
for food and attention.

Razib knows that this difference
in behavior

is all in their genes.

Khan:
Many of the changes in mammals occur in a group of genes

that are termed
neural crest genes,

and basically,
it's just a shorthand way

to say that it affects
the development of their brain.

And they're more childlike.

Freeman:
Every species of animal

has a set of chromosomes made
from thousands of genes.

Most of these genes
are common to all life.

When early farmers allowed only
the tamest offspring to breed,

a specific set of genes
mutated,

eventually giving rise
to the domestic goat.

[ Goat bleats ]

Those same genes in the wolf

mutated to give rise
to the domestic dog.

[ Dog barks ]

Wild aurochs
had these genes also.

When they mutated,

domestic cattle came to be.

[ Cow lows ]

In fact, nature uses essentially
the same genetic recipe

to turn any wild animal
into a domestic.

But one barnyard animal...
[ Cat meows ]

Is not like the others.

[ Cat purring ]

Obviously, you know,

unless you live
on the planet melmac,

you don't eat cats.

They are not a food animal.

But cats feed on mice,

and mice really,

really are attracted
to human granaries.

So it seems entirely likely

that cats were tolerated
in early human villages

because they served
a useful role

for the nascent farming
communities.

Freeman: Cats were not
intentionally tamed.

So Razib and his colleagues

looked to their DNA to see
how they became so friendly.

Khan:
We found in the study

that the comparison
to the wildcat,

the domestic cat exhibited
many changes in the genome

that have been seen
in other domestic organisms,

in particular, the genes

that seem to be involved
with docility.

So our study suggested
that the cat is, to some extent,

a self-domesticated organism.

Freeman: No farmer set out
to breed a domestic cat.

They domesticated themselves.

So that led Razib to wonder,
did we humans

also turn ourselves
into a domestic species?

Khan: Humans exhibit a lot
of changes in our genome

over the last 10,000 years.

My own personal opinion is yes,

you can define humans
as a domestic animal.

We live in large groups.

If you took humans individually
and put them on an island,

they really couldn't survive.

Freeman:
Compared with our wild ancestors 50,000 years ago,

we are more docile, slower,

weaker boned,

and more childlike.

But don't let that get you down.

The apparent downgrades
of domestication

have actually
given each one of us

a more important purpose
in life.

Khan:
A hunter-gatherer had to be Jack-of-all-trades because,

probably, there was
only 10 to 20 other people

that you interacted with
on a regular basis.

When you go up to a village
of 500,

you could have a warrior or two,

maybe someone
who specialized in healing.

Once you get to the size
of cities,

you have whole casts
of specialists that do things

that everybody else in the past
might have done.

Freeman:
When animals are domesticated, individuals in their populations

are more likely
to develop exceptional

and specific talents.

Humans are no exception.

It is what has kept
our civilization humming along.

Think of a farm.

It takes a lot more than
two people to keep it running.

Carpenters, mechanics,

arborists, veterinarians,

the farm relies on all of them

to develop their natural talents
into useful skills.

Razib nurtured his gift
of intelligence.

And now, his research adds
to our collective wisdom.

But he also
has another natural talent

that doesn't seem
to serve any purpose at all.

The one thing
that I can probably do

that impresses people is
i can eat hot peppers.

That's the one thing
where it's, like,

I'm pretty sure I can beat
anybody that I see and meet.

Freeman: Eating this pepper
would send most people

scrambling for water.

But for Razib, it's candy.

Our species thrives
because each of us feels driven

to purSue our own
highly specialized ambition.

But our individual purpose
in life may come to haunt us.

It could make our very reason
to exist obsolete

and mean lights out
for humanity.

Have you ever shared a funny
image with a friend online?

[ Camera shutter clicks ]

A meme made you do that.

But memes
aren't just Internet jokes.

They are any idea that spreads.

Great ideas, like those of
Da Vinci, Einstein, and Buddha,

are the reason
humanity has thrived.

In fact, memes
may be the real purpose of life.

We may exist
not to spread our genes,

but to spread ideas.

As long as the ideas reproduce,

we may be dispensable.

If you ask evolutionary theorist
Sue Blackmore

about a universal purpose
of all life,

she'll say it's to spread genes.

Blackmore:
So, my lovely chickens,

for example, those are
kind of living machines

that carry around the genes

and lay an egg
and carry on and so on.

And over the centuries
of domestication,

they've become nice, fat
chickens that lay lots of eggs.

That is what we might call
the first replicator.

That information,
coded in genes,

in the DNA molecules

in bodies of us,
chickens, trees,

that's the first replicator
on planet Earth.

Come on, chickens.
Come on.

Come on. Come on, chickens.
Come on.

Freeman: But humans have
one critical difference.

When we developed the capacity
for imitation and language,

we became vessels
for an additional replicator.

[ Cellphone rings ]
Hello?

- Freeman: The meme.
- Yeah?

Memes are the cultural
equivalent

of genes, if you like.

They are information that's
copied from person to person,

person to book.

They encompass all
of the habits, skills, stories,

that we pass from person
to person.

And they compete to use
our brains

to get themselves copied.

And in that way, they evolve.

Freeman: Like genes,
memes are selfish replicators.

They spread whatever they can,
regardless of the consequences.

Long ago, the meme

of fighting tribal enemies
with a stone axe

spread far and wide.

But it wasn't long
before a new meme arrived...

The meme
of fighting with a bronze sword.

Memes compete to survive.

The best memes
get their carriers to copy them,

remember them, and pass them on.

And just like bad genes,

the inferior memes
usually end up extinct.

When it comes to memes,

the same evolutionary
competition is going on.

The memes that we like,

or that provide something
for us,

or that trick us
into copying them,

they thrive,

culture fills up with them,

and the rest disappear.

Freeman: We are constantly
spreading memes.

A knock on the door is a meme.

A handshake is a meme.

There are countless other ways

to get someone's attention
behind a door

and countless ways
to greet them.

But in western culture,

these memes stuck.

In fact, Sue and her friends
are all spreading a meme

that came from the other side
of the globe...

Samba music.

Blackmore:
Our samba band is mimetic.

This interesting evolution
of samba

because it's evolved in Brazil
as street music.

So it's evolved to be loud,
active, fun, bright clothes,

to suit the sunshine
in the streets.

It comes over here to britain,

and we play the same music,

but it slightly changes
to fit in its new niche,

just like animals do when they

evolved into different
biological niches.

[ Cellphones chiming,
vibrating ]

Freeman: Memes have taken
the world by storm.

But now,
something new is coming...

The technological replicating
meme,

or the treme.

Blackmore:
Now, we have all this amazing silicon-based technology,

with digital information flowing
about all over the place.

This is a new kind of copying.

It's this digital information
that is competing

to use the resources of
all this information technology

that we've created.

Freeman:
Live music is a meme,

but music on your smartphone
is a treme

because technology can
effortlessly copy and share it.

Tremes can spread fast and wide.

They are often spread by
computers that don't need humans

to like, share, or tweet them.

Sue thinks that, someday,

when our computers
can spread and copy tremes

more effectively than we can,

we will all lose our uniquely
human reason for existing.

It sounds
like a dystopian nightmare,

but it may be something
we willingly choose.

Blackmore:
I think it's important to know

that this wouldn't be happening
if a lot of it weren't good

because we wouldn't
let it happen.

The only reason
that all these tremes

can take off the way they do
is because we want more music,

we want more books,

we want more fun videos,
informative videos.

And because these things

are chosen by us
and we like them,

we are willingly
producing all the hardware

and all the software
that is gradually taking over.

Freeman:
So, is this the ultimate purpose

of 3.5 billion years
of life on Earth,

to be replaced

by ever more sophisticated
information replicators?

It sounds strange.

But as physicists
begin to examine life's purpose,

they are finding
that life and information

could be one and the same.

What is the ultimate purpose
of life?

Is it to be cast aside
and replaced by machines

whose only pursuit
is information?

Well...

Some scientists now believe...

That we have always been nothing
more than evolving algorithms.

Physicist Sara Walker
is crafting a new definition

and understanding of life.

I think about biological systems
as physical systems.

But they're a unique kind
of physical system.

And they're uniquely defined,
really,

by the way
they handle information.

Freeman: Sara defines life
as a self-replicating algorithm,

a computational machine
that processes information

and then makes copies of itself.

[ Glass shatters ]

[ Glass shatters ]

It's a concept that really
hits home for Sara...

Now that she's made
a little algorithm of her own.

What's amazing about having
a small child in your home

is how they learn things.

Look at that big mess.
What is all that stuff?

So he's really
just like an information junkie,

running around the house
being like, "what is this,

what is this, what is this?"

And so it's pretty fun.

Freeman:
Sara sees her son, corwin,

as a collection
of logical processes

working hard to solve
the problems of staying alive...

In other words, an algorithm.

And everything he does,

he's processing information
about the world he lives in,

even when he's doing his best
to just eat lunch.

Eating is definitely
information processing.

You're taking chemicals
from your environment,

and you're ingesting them,
and your body has to actually

be able to figure out
how to use those chemicals

for the right kind
of chemical reactions.

Freeman:
Sara believes that corwin

and all of us humans
came to be because evolution

guided life to become
better information processors.

Walker: I do think
evolution has an arrow.

I do think it actually evolves
toward more complex systems

and better information
processing systems.

Freeman: Evolution's arrow
locked living organisms

into an information-gathering
arms race.

Vision and hearing get sharper.

Teeth and claws
get better at grabbing prey

and sampling the information
in its meat.

Sara believes everything we do
follows this evolutionary drive

to gather
and decode more information.

Yay, good job, corwin!

Freeman: In fact,

even the technology
that we create

follows the same pattern.

So one thing that you
might think we humans want to do

is remember what our kids
look like when they're little.

So originally,

people used to capture
that kind of memory or image

by actually painting it, right?

And then, we figured out
something very clever,

which is that we can actually
just capture the light and store

that image
from the light we capture.

[ Camera shutter clicks ]

And those are cameras.

Freeman:
The information-gathering algorithms of cameras

are evolving, too.

Digital cameras evolved
to process more information.

They record full color

and even recognize
when a face is present.

Then came the smartphone camera,

which can even figure out
who that person is.

Walker:
And we've now evolved technology

which is helping us
process information even better.

Not only humans
fit in this framework,

but even our modern
social systems

and our technological systems
are sort of a natural outcome

of the way
the universe operates.

Freeman:
Biology and technology are locked together

in a joint quest
for more information.

In fact, this could be
the ultimate purpose of life.

Walker: Evolution is really
about capturing

more information
about the environment.

And through that process,

the environment
becomes more complex.

Living systems
fundamentally change

the universe that they're in
and use that

to do the kind of amazing things

that we,
as biological systems, do.

Perhaps that actually is
the purpose of living systems,

is to figure out
how the universe actually works.

So living systems,
in this kind of framework,

are somewhat fundamental
to the universe

because they're the way
the universe figures itself out.

Freeman: Life is an epic quest
for knowledge.

I'd love to think we humans will
reach the end of this long road

and know everything there is
to know about the universe.

But evolution
may have other plans.

Our thirst for information

could soon wipe us
from the face of the planet.

It is common
to think of evolution

as progress,

species locked in a struggle

to become the fastest,
the strongest,

and the tallest,

reach ever-higher levels
of complexity and skill.

But life is not
an ever-growing edifice

of biological refinement.

It's a series
of dramatic collapses.

Jim Sethna is a physicist
at Cornell.

He researches the fine line

separating success
from catastrophic failure.

These rice krispies could sit
on the shelf for years.

But expose them to milk,

and they crackle
as they collapse into mush.

Most of the systems
we see crackling noise,

it's at a transition
between two different states.

So in the rice krispies,

it's a transition
between the dry state

and the soaked state.

Freeman: Jim is interested
in how any system behaves

when it sits on the knife's edge

between stability
and crackling apart,

a so-called critical point.

A burning log crackles

as pockets of air,
small and large,

expand in rapid succession.

Mountain snow builds up

until a tiny movement escalates
into a crackling avalanche.

Jim and a growing group
of scientists

believe that our own bodies

are also poised
at the edge of collapse.

Ironically, it's what has
kept us out of harm's way

for millions of years.

[ Car door closes ]

Think about our sense
of hearing.

Evolution pushed it so close
to a tipping point

that a tiny change
in the air around us

causes a cascade
of thoughts,

senses,
and images in your brain.

Your hearing is so finely tuned

that,
if it were any more sensitive,

you would be sensitive
to the random motions

of air molecules
hitting your eardrum.

Freeman: Our eyes
are even more sensitive.

A single photon can send
billions of neurons

crackling into overdrive

and conjure up
a phantom that isn't there.

Species have developed
all kinds of senses,

and each of them has been,
over billions of years,

honed to the absolute limits.

Freeman: In fact, being poised
between function and collapse

is the normal state

of every functioning cell
in your body.

Jim and his colleagues,

eshan mitra and Sarah Shelby,
are investigating why.

The membrane of a human cell
exists on a knife's edge.

When there's a tiny change
in the outside environment,

the structure of its fats
and proteins instantly collapses

and rearranges itself.

Sethna: Its cells have to be
very finely tuned

to distinguish
the things it wants to expel.

They sit near
this critical point

in order to make it easy

for the cell to respond
sensitively and quickly

to new information
about its outside.

Freeman: The membranes of cells
exist on the border of disorder.

The same is true for the systems
of cells

that comprise our senses.

And as Jim is learning,

entire systems of organisms
can also teeter on the edge.

Consider the mesmerizing
movements

of flocks of starlings.

It is virtually impossible

for a predator
to feast on this flock.

The movement of one bird

changes the entire shape
of the murmuration.

Each bird is sort of programmed
in its head

to fly in roughly the same
direction as its neighbors.

But it's tuned in this way

so that they're at the border
of stability,

and that is what makes them
respond quickly and efficiently

to their environment.

Freeman:
Dinosaurs were also poised at the knife's edge.

Their massive size optimized
them to weather any predators.

But optimization
always comes at a price.

Sethna:
When you optimize things,

they naturally end up
at some kind of critical point

because you're trying to milk as
much as possible out of a system

before you hit a catastrophe.

Freeman: A change in climate
eradicated the dinosaur.

A single miscue
can collapse a murmuration.

A few aberrant neurons

can trigger an epileptic fit
inside the human brain.

A cell's membrane can collapse
into a state of disarray

and die.

And human life itself

may also be poised
for a dramatic collapse.

After all,

we constantly optimize ourselves
to the point of failure

and hold on as long as we can.

Jim, however, is hopeful.

In spite of our never-ending
quest to better ourselves,

we have one critical talent
to prevent catastrophe.

We have an unusual advantage
that we are a system

that's at a critical point
when it's self-aware,

that is able
to analyze the problems

and avoid the disasters,

which are getting more serious

if we get better
at controlling the world.

Freeman:
If lives are built to so easily come crackling apart,

what's the point?

This scientist says
that it's really quite simple.

The point of it all

is to discover
the point of it all

because when you think
about purpose,

everything changes.

Is humanity on a path

to knowing all there is to know
about the universe?

Or are we bound to be replaced?

It's hard to think
about our ultimate purpose

when everyday life can be filled
with so many hurdles.

But that may be a mistake

because taking the time to think
about why we are really here

could be what makes those
daily struggles much easier.

We call came from somewhere,

and we all have somewhere
we want to go.

Psychologist Tony burrow

has thought about this journey
his entire life,

which began
with his atypical family.

When I was two months old,

I was adopted
by two white parents.

When you have parents

who are of different
racial background than you,

it gives you a lot
of opportunities

to talk about race.

I wanted to know...
How do people who experience

chronic forms
of discrimination and oppression

deal with this?

And for me, this gives rise
to questions of purpose.

Freeman:
Hiking is walking with purpose.

There is an end goal,

but that's not why people
like Tony

go through all the trouble
of reaching the trail's end.

Tony thinks
that having a purpose in life

is not only necessary
for happiness,

it subconsciously changes how we
perceive ourselves and the world

around us.

Tony is a professor
at Cornell university,

where students every morning
face an infamous challenge,

a figurative and literal
uphill climb... the slope.

This 500-foot-long ascent

is the wall
between a warm, cozy bed

and a long day
of intense classwork.

Burrow:
So a couple of semesters ago,

a student came up to me after
class and said, "professor,

I'm really sorry I couldn't
make it to class last Tuesday."

And he said, "you know, I really
just couldn't get up the slope.

I didn't have the energy."

And I started to think about it.

Was this a question
of motivation?

Excuse me.

Do you have a few minutes
to participate in a study?

Oh, sure.

Freeman: As students begin
their journey,

he asks them what goal they want
to accomplish that day.

At the top of the slope,

a researcher asks them
how difficult the climb was

and to estimate
its steepness.

Burrow: So we found a strong
and reliable relationship

between the angle
that they perceived

after ascending the slope

and the degree of effort

that they said was necessary
to get to the top.

Freeman: The steeper you feel
the slope is,

the more effort you think
you've expended to climb it.

No big surprise there.

But Tony adds a twist.

He asks some subjects,
at the bottom of the hill,

to write not about their goal
for the day,

but their long-term purpose
in life.

Burrow: A goal is terminal.

It's something
that you can accomplish.

A sense of purpose
is a broader framework

that describes and orients
who one approaches the goals

that they've laid out
for themselves.

So we don't think of purpose

as something that
you can actually accomplish.

Freeman:
Students prompted to think about their life's purpose

still thought the climb was just
as brutal as the other group,

but they didn't mind it

while the students
contemplating their daily goals

often struggled.

The purpose-minded group

tackled the hill
with a sense of purpose.

Tony believes having a purpose
frees us

from feeling the full weight
of the obstacles in front of us,

whether a literal hill
we must climb

or a personal challenge
we must overcome.

Burrow:
I think what purpose does, first and foremost,

is reminds people
that where they are right now

is not forever,

that they're heading
in a particular direction.

And just like
when we're on a hike,

it doesn't really matter

if you're confronted
with a challenge.

The goal is to continue to hike.

And for individuals who can
cultivate a sense of purpose,

they may begin to see other life
challenges in the same way.

Freeman:
In our lives, having a purpose

can flatten the mountains
between where we are

and where we're going.

Are we here, now,
alive, for a reason?

People like Ann frank
and Nelson mandela

asked that question
in their darkest hours.

Their determination to make
a reason for life

gave them the strength
to carry on

and the power
to shape the world.

Life may not have
one unifying purpose,

but that shouldn't stop us all
from searching for it.

Finding a reason
and believing in it

may be all the purpose
that we need.

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